Color printing attachment for web printing presses



May 12, 1936. E. J. WATKINS 2,040,226

COLOR PRINTING ATTACHMENT FOR WEB PRINTING PRESSES Filed Dec. 10, 1934 Patented May 12, 1936 PATENT OFFICE COLOR PRU; TING ATTACHMENT FOR WEB nmrmc PRESSES Edward J. Watkins, Monrovia, an. Application December 10, 1934, Serial No. 756,736 2 Claims. (or 101-173) This invention relates broadly to the art of multicolor printing and has to do more particularly with attachments for e sting mono-color continuous web presses whereby two-color printing may be efiected. v

An object of the invention is to adapt monocolor or single impression web presses for twocolor work at small expense and without reducing their capacity.

In continuous web printing presses it is necessary to provide a pair of feed rollers for pulling the web on the roll of news print and through the press, one roller delivering the web to the printing mechanism and the other pulling it through the printing mechanism and delivering it to the folding mechanism. These feed rollers must at times maintain exactly the same peripheral speeds else the web will be broken or will become slack in the press. For this reason they are rigid, usually being constructed of steel or iro and are geared together to run in synchronism with each other and with the printing mechanism.

In. accordance with the present invention, I

position a printing cylinder or cylinders to print on the web as the latter is passing over one or both feed rollers whereby the latter serve as backing members to support the web as the type is pressed thereagainst. Since thefeed rollers have rigid and unyielding or faces are made of rubber or other yielding resilient material to permit compensation for slight and unavoidable irregularities in the printing surfaces.

Although the invention is applicable to both cylinder and flat bed printing presses, it has a larger field of usefulness in connection with flat bed presses and will now be described in connection with a conventional flatbed web press.

In the drawing: Fig. 1 is a schematic diagramof a duplex flat bed web press equipped with my attachment;

Fig. 2 is a vertical detailed view, partly in section, of one of the feed rollers and a printing cylinder associated therewith in accordance with the invention; and

Fig. 3 is an enlarged through a portion of the trating the manner surface thereto. 7

Referring first to the schematic diagram of Fig. 1, that portion of the drawing that relates to an existing press is shown. in light lines and the additional printing cylinders to be attached in accordance with my invention are shown in heavy lines.

printing cylinder illusof attaching the printing uniform speed. The

surfaces the printing face detailed sectional view idler rollers 23, 24,

compressing the web thereagainst.

The printing press itself comprises a feed roller I which continuously draws a web 2 from a roll of news print 3 and delivers the web over idler rollers 4, 5, and 6 to a lower printing mechanism comprising a pair of idler rollers 1 and 8 and an impression cylinder 9. I From the roller 8 the web 2 is passed over a pair of idler rollers I0 and II, thence back to anupper printing mechanism comprising idler rollers I 2 and I3, and an impression cylinder I4, after which the web is 10 passed over an idler roller I5, under an idler roller I6, thence over a second drive cylinder I1, and thereafter under an idler roller I 8 to a cutting and folding mechanism which has not been shown since it is immaterial to the present invention.

The two drive rollers I and I1 are. rigid rollers and are of steel or iron geared together and to a driving motor to continuously feed the web at a impression cylinders 9 and I4, together with their associated idler rollers I, 8, I2. and I3, are all mounted on a reciprocable carriage and are reciprocated back and forth to carry the cylinders 9 and I4 over the stationary type beds I9 and 20, respectively, the mechanism for reciprocating these elements being driven from the same mechanism which rotates the drive rollers I and I! so that they all work in synchronism.

Of course, an inking mechanism is provided for inking the type beds I9 and 20 but since these mechanisms are old and well known and have nothing to do with the present invention, they are not disclosed. During the intervals while the impression cylinders 9 and I4 are rolling over the type beds I9 and 20, the movement of the web 2 is stopped. During these intervals the slack -which would otherwise accumulate between the drive roller I and the impression cylinder 9 is taken up by the idler roller 6, which is mounted on a lever 2|, which is resiliently retracted by 40 springs not shown. At the same time the idler roller I5 moves to the left by a corresponding amount to permit the continuous feeding of the web over the drive roller I1. To maintain the r web 2 infirm frictional engagement with the feed rollers l and I1, a belt 22, mounted on three small and 25, is positioned adjacent each roller I and I I, the belt following the curvature of the roller in each instance and firmly In. the operation of the press as described, which is familiar to all those versed in the printing art, the impression cylinder 9 first forces the web 'Z-against the printing bed I9 to print on one side of the .web and then later as theweb tween the beds add to a press of the type describe the progresses through the press the same portion of the web is forced by the impression cylinder l4 against the printing bed to print onthe opposite side, the length of the loop of web bel9 and 20 being adjusted by the proper positioning of the idler rollers 10 and II so as to insure proper registration of the printed matter on the opposite sides of the web.

In accordance with the present invention, I described a pair of auxiliary printing cylinders 21 and 28, respectively. These cylinders are identical and are each connected to their associated driving roller in identical manner so that it will be sufficient to installation of the cylinder 21.

Referring to Figs. 2 and. 3, cylinder 21 comprises a hollow tubular member 29, preferably of iron or steel, suitably supported as by spokes 30 on a shaft 3|, which extends beyond the cyl- 20 inder 21 at each end and is rotatably supported in bearings provided therefor in the main frame 32 of the printing. press. Mounted upon the shaft 3| at one end of the cylinder 21 is a hub 33 which is keyed to the shaft by a key 34. This hub 33 in turn supports a gear 35 which meshes with a gear 31 mounted upon the shaft 38 of the drive cylinder 11. This shaft 38 may be driven through a beveled gear 39 mounted upon the opposite end, which mesheswith a suitable drive pinion connected with the mechanism of the press. c

The construction of the hub 33 and gear permits rapid removal of the gear 35 from driving relation with the hub 33. Thus by merely 35 removing the cap screws 36, the gear 35 may be slid out of mesh with the gear 31. This is done whenever it is desired not to use the color printing cylinder.

- The number of teeth in the gears 35 and 31,

40 respectively, is so chosen relative to the diameters of the drive rollers 11v and the printing cylinder 21 that they travel at substantially the same peripheral speeds Actually the cylinder 21 travels slightly slower because of the fact that the type thereon extends outwardly beyond the surface of the cylinder and it is desired that the surface of the type travel at the same speed as the web which rides over the drive cylinder 11.

The area of the printing surface 40 on the cylinder 21 varies widely according to the particular requirements of the job at hand. Ordinarily the cylinder will be employed to add red or green (or any other color for that matter) headings or inserts to a page of printed matter, the

major portion of which will be printed in black from, the usual printing face 19. Thus in Fig. 2 the web 2 has been completely printed in black from the. type bed l3, withthe exception of a 66 blank space 41 which is to be printed in color 70 known in the printing art 75 strip of cardboard from the cylinder 21. In this instance the cylinder 21 therefore. carries a small printing surface 43 dimensioned to fill the blank on the web. As previously indicated, the printing surface on the cylinder 21 must be resilient to work satis-v factorily against the rigid drive cylinder 11. I

prefer to employ a printing surface of rubber since methods of producing such faces are well and they'can be made quickly and at small expense. The rubber printing face must be securely fixed to the surface of the cylinder 21 and I have found it desirable in practice 'to first mounton the cylinder 21 a or other-porous fibrous maspace 4| with reference to a particular installation on a terial 42 and then aflix the rubber printing face 43 to the cardboard, the cardboard being affixed to the cylinder 21 by a suitable cement and the rubber printing face 43 likewise being cemented to the cardboard 42. I have found this procedure to be much more satisfactory than cementing the rubber mat or face 43 directly to 'the surfaceof cylinder 21 because the cements that are suitable for the purpose are extremely slow in setting when used between two non-porous surfaces. However, when the cement is used against a porous surface, such as the cardboard 42, it sets very rapidly.-

It is highly desirable, if not absolutely necessary, in an attachment of the type described to be able to quickly and accurately properly position the printing surface 40 on the cylinder 21 so that it registers with the other printed ma ter on the web. To this end, I subdivide the surface of the cylinder 21 by longitudinal lines 46, 'these lines being spaced circumferentially to indicate, in terms of lines, the vertical position on the printed sheet. Thus the'line labeled T on the right end of cylinder 21 indicates the top of the printed page and the line B immediately therebelow in 'cates the bottom of the printed page. The side margins of the printed page may also be indicated by circumferential lines 44 engraved in the surface of cylinder 21.-

The device may be set up and operated in the following manner:

l9 has been prepared and that certain blanks have been lefttherein for the insertion of color matter. At the same time the rubber printing surfaces, corresponding in dimensions to the blanks left in'the bed 19, are prepared. They are then cemented to the surface of the cylinder 21 (with a cardboard backing as previously described) in the proper position to register with the blank areas of the bed. 19, the circumferential positioning of the printing face 40 being determined by following the longitudinal lines 43 and the lateral position being determined by suitably spacing the surface 40 from one of the marginal -lines 44. The press is then set to a predetermined normal position; rotated until one of the longitudinal calibrating lines, labeled R on the left margin, is aligned with a pointer 45 secured to the frame of the press. The gear 35 is then placed in position on the hub 33 and locked in place by inserting and tightening the cap screws 36. By following the foregoing procedure the press may be set up and operatedwithassurance that the color inserts will be accurately registered with respect to the black printing matter.

Inking mechanisms 21a and 28aare provided for the auxiliary cylinders 21 and 28, respectively, but since these mechanisms are well known, they are merely schematically illustrated in Fig. 1 and need not be described in detail.

Although the invention has been described flat bed press, it is to be understood that various modifications can be made in the structure disclosed to better adapt it to special operating conditions without departing from the spirit of the invention and' the invention is therefore, to be limited only as set forth in the appended claims.

I claim: 1 1. A flat bed web printing press comprising a printingmechanism and two rigid feed rollers, one of which feeds a web to the printing mechanism and the other of which discharges the web Assume that the printing bed then the cylinder 21 is v from the printing mechanism, in combination with -an-auxiliary printing cylinder having a resilient printing face thereon and positioned to print on the web as the latter passes over one of said feed rollers whereby the-rigid Ieed'roller constitutes a backing member to compress the web asainst the auxiliary printing cylinder, and

means for driving said auxiliary cylinder in-synmrovided in association with said other feed roller 5 iorprinting on both sides of the web.

EDWARD J; WATKINS. 

